"The government has reported its combined environmental liabilities at $7.7 billion," writes Vaughan. "Many of these sites are buried and out of the public eye, but they will impose human health risks and environmental and financial burdens for generations to come."

"We cannot go back and repeat the errors of the past. I don't think Canadians can afford it and I don't think they would actually accept it," Vaughan told reporters.

"When you look at the legacy of contaminated sites right across this country, this is a legacy that Canadians will be paying for – not for decades. They'll be paying for it literally for centuries," Vaughan added.

The report’s two other chapters dealt with Canada’s approach to dealing with greenhouse gas emissions (GHGs).

Targets beyond reach

The chapter about the government’s new 2020 GHG target found the easier-to-meet, Kyoto Protocol replacement goals were still far out of reach.

"Environment Canada’s own forecast shows that in 2020, Canada’s emissions will be seven per cent above the 2005 level, not 17 per cent below it," Vaughan pointed out.

The big problem appears to be the government’s sector-by-sector approach. Each set of regulations takes up to five years to develop.

So far, only three sets of regulations have been written. There are two for the transportation sector, which are in place, and one for electricity, which doesn’t come into effect until 2015.

There are no regulations yet for the oil and gas sector, which is the fastest-growing GHG emitter, accounting for one-fifth of Canada’s total emissions. The auditor notes that regulations for this sector are expected to be made public by December.

Some experts were skeptical about the date for those oil and gas rules.

"I have seen governments say 'might' for almost three decades now on climate, and about 95 per cent of the 'mights' became 'nots.' So a government that says 'might' for a regulation should not, according to the very strong historical evidence, get credit until the 'might' becomes 'is,'" said Mark Jaccard, a professor at Simon Fraser University's school of resource and environmental management, one of Canada's leading experts on climate change.

Scott Vaughan, the federal commissioner of the environment and sustainable development, says the government is behind schedule in meeting its 2020 greenhouse gas emissions reductions. (Sean Kilpatrick/Canadian Press)

All this is compounded by the lack of an overall implementation plan to show how the government’s multiple regulations will lead to the end goal of GHGs falling 17 per cent below 2005 levels.

Vaughan also noted Ottawa hasn’t costed its plan.

"The government said it was withdrawing from the Kyoto Protocol because remaining in it would be too costly to the Canadian economy. We therefore expected the government would have estimated how much it will cost to meet its target and identified the least-costly options," the report said.

Absence of dollar figures raises fears

Environment Minister Peter Kent accepted the commissioner's recommendations, but took issue with the costing critique.

"Asking for costing in advance of consultations with industry and the provinces would be premature and speculative," a spokesperson from Kent's office wrote to CBC News.

"These regulations are not being created in a vacuum in Ottawa. Costing is one of the elements of consultation with provinces and industry," the spokesperson added.

The opposition echoed the commissioner's concerns about the absence of dollar figures in the government's 2020 plan.

"We seem to be uncovering a pattern with this government. It always seems to be two sets of numbers. Are they hiding these numbers? Are they incompetent? Was this a typographical error? How can we know for sure?" asked the NDP's environment critic Megan Leslie.

Kent's office also contests the commissioner's claim that "Environment Canada's own forecast" showed the government would not meet its 2020 targets.

His spokesperson said that forecast was "speculative" and based on a report published in 2009, before many of the current sector regulations were written.

The report's other chapter about the Kyoto Protocol Implementation Act found Canada will not meet the targets set in the 1997 agreement.

Kent announced Canada would pull out of Kyoto last year. The budget implementation bill currently up for debate in the Commons, C-38, would repeal that act.